Flood Prevention System and Method

ABSTRACT

A flood defense system includes a perimeter barrier around an asset or zone to be protected and a soak way system disposed sub-surface within the protected zone and designed to collect surface water from within the protected zone. A sump is provided within the protected zone and includes a pump for pumping water from the sump outside the protected zone beyond the perimeter barrier. A series of sensors senses for the presence of ground water inside and outside of the protected zone and within the sump and a control unit coupled to the sensors controls the operation of the pump in order to remove water from the sump at a rate sufficient for preventing, or at least reducing, flooding within the protected zone. A control unit can provide warning of impending flooding.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority benefits from UK patent application GB1504764.0 filed on Mar. 20, 2015 entitled “Flood Prevention System and Method”. The '764.0 application is hereby incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to a flood control system and method and in the preferred embodiments to a system and method able to prevent, or at least reduce, floodwater ingress into an asset, such as a dwelling or other building or location within a protected zone.

BACKGROUND OF THE INVENTION

Flooding is a phenomenon which is experienced in many countries and has devastating consequences on inhabitants and businesses. Environmental changes are also bringing flooding to areas not previously affected and increasing flooding in flood prone zones.

A variety of flood defenses have been developed, most of which involve the construction of permanent high barriers around a zone to be protected, as well as more traditional approaches such as use of sand bag barriers. Such approaches, while able to mitigate the effects of flooding to some degree, are often not effective, particularly when flooding causes an increase in the water table within the area sought to be protected.

Examples of drainage systems in a building are disclosed in U.S. Pat. No. 5,501,044 and U.S. Pat. No. 6,575,666. These systems have limited application particularly in protecting assets in a flood area.

SUMMARY OF THE INVENTION

A flood management system seeks to provide an improved system and method of preventing, or at least reducing the likelihood and/or severity of flooding within an asset protected zone and in some preferred embodiments the system optimizes flood water management.

The flood management system protects an asset from flood water, by creating:

a perimeter barrier disposed alongside and around an asset to be protected, the barrier including an upstanding wall for blocking surface water ingress into the protected asset and a subsurface barrier wall, the barrier wall being a discrete structure from the asset to be protected;

a drainage system within the protected asset including at least one drainage unit disposed subsurface and adjacent the subsurface barrier wall;

at least one subsurface sump to which the drainage system is fluidically coupled for collecting water from the drainage system, the at least one sump having a water level sensor disposed to sense water level in the sump;

a pumping unit connected to the at least one sump;

a drainage conduit coupled to the pumping unit, the drainage conduit extending beyond the perimeter barrier outside of the asset; and

a trigger mechanism coupled to the water level sensor and the pumping unit, wherein the trigger mechanism is operable to activate the pumping unit when the water level in the sump reaches or exceeds a threshold level so as to remove water from the sump and thereby from the asset.

The asset can be a building but more typically can be a zone which includes at least some ground surface. In one example, the zone can incorporate one of more buildings such as houses, gardens, driveways and so on. In another example, the zone can include a sports pitch, an industrial unit, hospital and so on, even a park area and pond.

The system provides a barrier wall, impervious to flood water, which can surround the asset. The other elements of the system ensure, or at least improve the chances, that the asset can remain dry, not only from water ingress outside the asset and barrier wall but also, in some preferred embodiments, from water arriving into the asset such as rain water. Some preferred embodiments act to manage the water table within the asset, that is in the area delimited by the barrier wall, such that the ground and buildings within the assets remain dry. In practice, this is achieved by managing the water table, achieved by the positioning of the drainage, sump or sumps and pumping of water out of the asset. The water table in the asset can very well be different from that outside the asset, typically lower, ensuring that the asset remains dry.

Thus, in some embodiments, the asset can include at least one building, wherein at least a part of the at least one building is spaced from the perimeter barrier. The asset can include exposed ground surface.

The barrier is preferably a low lying wall. In the example described below, the upstanding wall has a height of around 800 millimeters, and typically is preferably less than 1.5 meters or 1 meter. In practice, the upstanding wall should preferably not be above head height and most preferably of a height consistent with a low lying garden wall.

The at least one drainage unit is preferably a drainage channel, although in some embodiments could be a bore hole or other drainage mechanism, coupled to a sump. As the preferred embodiments use drainage channels, they are referred to as such in what follows, though that systems could also be designed with other drainage mechanisms.

Preferably, each drainage channel is spaced from the subsurface barrier wall. Most preferably, each drainage channel is spaced from the subsurface barrier wall by a distance permitting flow of ground water passing under the subsurface barrier wall into the channel or channels. In a practical embodiment, the each drainage channel is spaced around one meter from the subsurface barrier wall. There can be provided other drainage channels, or units, further into the asset, or protected zone.

The at least one drainage unit is preferably disposed at a depth substantially the same as a depth of the subsurface barrier wall.

The at least one drainage channel can be open at a top thereof at least adjacent the sump. The at least one drainage channel can be connected to the sump at a depth lower than a threshold water level. In practice, this arrangement can allow for rain water to be drained naturally into the ground, by spilling out of the drainage channel or channels without operating a pumping unit in the sump, which can save substantial energy usage.

The threshold water level is an acceptable water table level in the asset. In practice this can be a level at which the water table does not rise above ground level, that is does not lead to flooding in the asset, or protected zone. In some embodiments, the threshold level can be chosen to be below ground level.

Advantageously, the system includes a pumping unit disposed to pump water from the sump to outside the asset. The pumping unit can include one or a plurality of pumps. In some embodiments, both pumps are activated when water flow is determined to exceed a threshold rate.

The system can include a water level sensor disposed to measure water level in the sump. The water level sensor can be a hydrostatic sensor.

Preferably, the system includes one or more sensors for measuring surface or ground water inside the asset and/or one or more sensors for measuring surface or ground water outside the asset. These sensors can also be hydrostatic sensors.

Advantageously, the system includes a control unit coupled to the sensor or sensors, the control unit incorporating or being coupled to the trigger mechanism. The control unit can be disposed in the asset. Preferably, the control unit includes a telemetry unit to monitor and manage water levels and pump unit activity, and a communications unit to send flood related alerts and/or alarms to a remote management station.

A method of protecting an asset from flood water includes the steps of: forming a perimeter barrier alongside and around an asset to be protected, the barrier including an upstanding wall for blocking surface water ingress into the protected zone and a subsurface barrier wall, the barrier wall being a discrete structure from the asset to be protected; forming a drainage system within the protected asset, the drainage system including at least one drainage unit disposed subsurface and adjacent the subsurface barrier wall; providing at least one sump subsurface in the protected asset, to which the drainage system is fluidically coupled for collecting water from the drainage system, the at least one sump having a water level sensor disposed to sense water level in the sump, a pumping unit being connected to the at least one sump; providing a drainage conduit coupled to the pumping unit, the drainage conduit extending beyond the perimeter barrier outside of the asset; a trigger mechanism being coupled to the water level sensor and the pumping unit, wherein the trigger mechanism is operable to activate the pumping unit when the water level in the sump reaches or exceeds a threshold level so as to remove water from the sump and thereby from the asset.

The method can usefully provide an apparatus which can be fitted to an existing asset, such as a house and garden, a group of houses of a village, an industrial unit and surrounding ground space, a sports facility such as a football pitch, and so on. It is not necessary to modify the structure of the asset itself

In some embodiments, therefore, the asset can include at least one building and wherein the perimeter barrier is at least partially spaced from the at least one building. The asset can include exposed ground surface.

The method preferably includes the step of determining water porosity of soil where the perimeter barrier is to be formed and determining the depth of the subsurface barrier wall on the basis of the determined soil porosity.

Advantageously, the subsurface barrier wall is formed to have a greater depth in porous soil and a lesser depth in less porous soil.

The method can include the step of spacing the at least one drainage unit from the perimeter barrier. Preferably, the method includes the step of determining the spacing of the at least one drainage unit on the basis of the porosity of the soil. It can also or alternatively include the step of determining the depth at which the at least one drainage unit is disposed on the basis of determined soil porosity.

The preferred embodiments of system disclosed herein can provide:

a) a barrier built around a property or other area to be protected, which prevents, or at least reduces the chance of and/or severity of, surface water entering the protected area while allowing access for pedestrians and vehicles;

b) a drainage system that removes ground water from below and surface water from above the property;

c) a pumping system that evacuates collected water to outside the barrier;

d) a local control system that operates the pumping station;

e) a telemetry system that allows remote management of the system and for instance SMS and email alerts to designated recipients.

The barrier preferably has at least one opening, such as a gate which can be left open and closed when the asset requires protection, such as when water is detected either within the area of the asset or outside the barrier, or both.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a flood defense system.

FIG. 2 is a plan view of the detail of an example of a part of a flood defense system.

FIG. 3 is a plan view of the detail of a part of a flood defense wall.

FIG. 4 is a plan view of the detail of an example of a part of a flood defense system similar to FIG. 2 and showing a plurality of sensor elements;

FIG. 5 is a transverse cross-sectional view of a part of a flood defense wall of the embodiment of FIG. 4;

FIG. 6 is a cross-sectional view of an embodiment of sump.

FIG. 7 is a cross-sectional view of another embodiment of sump.

FIG. 8 is a schematic diagram of a control unit for the system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

The term “asset” used herein refers to the contents of the area protected by the system and method taught herein. The asset can include one or more buildings, ground level structures such as gardens, paths, roadways and so on. The term “protected zone” is used to denote an asset or the area of an asset.

FIG. 1 shows in schematic form an embodiment of flood defense system 10 for protecting an asset, which in this example includes a building, such as dwelling 12, and surrounding garden, from being flooded. System 10 includes perimeter barrier 14 which surrounds building 12 and specifically the entire asset or protected zone 22. Barrier 14 can include one or more access points(not shown), such as openable flood gates, for gaining access to the asset or protected zone 22 and building(s) 12 located within zone 22. Flood gates and other access points can provide openable or removable fluid impermeable panels disposable in associated openings in wall 14. When closed, the flood gates and wall are an impenetrable barrier to protect the zone or asset within the barrier.

Perimeter barrier 14 includes a first upstanding wall 16, which is constructed to have a height sufficient to be greater than the maximum expected height of surface flood water 18. In practice, the wall is preferably below eye level height, such as less than 1.5 meters, preferably less than 1 meter. In practice, if potential flood water will exceed such heights, the wall could be made higher.

Barrier 14 also includes buried footing 20 which acts not only as a support foundation for the upstanding wall 16 but also as a subsurface barrier wall useful in reducing the level of the water table within protected zone 22.

Perimeter barrier 14, and in particular upstanding wall 16 and buried footing 20, can have varying heights and depths in dependence upon the lay of the land around the perimeter of protected zone 22, so they can be greater in cases where parts of the land is at a lower altitude, and lesser where the land that is at a greater altitude, for example. Furthermore, the depth of buried footing 20 can also be varied in dependence upon the nature of the ground. Specifically, subsurface barrier 20 has a depth which controls the flow of ground water into protected zone 22 and the amount of ground water permitted within protected zone 22. Typically, footing 20 will be deeper in more porous soil and shallower in less porous soil. Where the soil is impervious, the footing can be very shallow and in some instances omitted.

Barrier 20 is a separate structure from the asset, including buildings in the asset. Specifically, the barrier preferably does not form part of a protected building per se, such that the barrier can be constructed after and around such buildings. The barrier can be close to or abut a building in some embodiments, but remains a distinct structure. The barrier can be physically connected to a building, such as being positioned up against the wall of a building. In some embodiments, barrier 20 is not positioned below a building.

Within protected zone 22 there is provided at least one buried channel and/or drain 32, 34 and these preferably extend alongside but are spaced from perimeter wall 14, and are coupled to sump 30, which is a buried water collection chamber.

Sump 30 has dimensions, in terms of depth and diameter, which enable sump 30 to store sufficient quantities (volume) of collected water before being pumped out of sump 30, and also for retaining the level of water within sump 30 to below a preferred level, indicated in the drawings by reference numeral 40. This will in practice, provide a limit to the water table within protected zone 22. Disposed within sump 30 is a pumping unit, and a conduit or tubing for taking water out of protected zone 22, as depicted by the arrow 44 in FIG. 1.

Drains 32 and 34 are disposed at a depth consistent with the depth of subsurface barrier 20, typically being at substantially the same depth although they can be slightly higher or lower than this. Drains 32, 34 are also spaced from subsurface barrier 20 to allow for ground water from outside the protected zone to flow into drain 34, as depicted by arrow 46. Typically, drains 32, 34 will be around one meter from subsurface barrier 20, although this will be dependent upon the porosity of the soil.

The drains are typically buried open channels able to allow the flow of water there along, and are connected to sump 30 so that the water they collect is fed into sump 30 for removal from protected zone 22.

Prior to installation of system 10 one or more surveys are undertaken around property 12, the perimeter of the protected zone and the ground within the protected zone, as well as the local environment. These surveys are intended to determine factors such as: mean water table level, soil state and geological composition, particularly soil permeability, historical risk of flooding and historical flood levels. The results of the survey are then used to design a bespoke flood protection system for property 12. Specifically, the variables can typically include: subsurface barrier wall 20 depth, barrier wall 16 construction and height, drain depth, dimensions and position relative to barrier wall 14, pumping station (sump 30) capacity, as well as placement of sensors 102-106.

Barrier wall 14 in some preferred embodiments is formed of four primary components. Buried footing 20 is in the form of a concrete foundation. Upstanding wall 16 preferably includes an anchor system of rebar and steel mesh, a composite construction panel comprising an insulated polystyrene core approximately 50 mm in width encased in a welded wire mesh either side, which connect to each other via braces shot through the core and welded in place. On the outside of the frame and skeleton structure, there is preferably a dry spray concrete, such as spraycrete, as a layer between 50-100 mm thick encasing the construction panel and rebar.

Subsurface barrier wall 20 is laid down around the periphery of zone 22 to be protected according to specifications determined during the site survey. The concrete used is preferably high density and waterproof, with a system of rebars and mesh reinforcements (not shown) set in place before the concrete is poured/sprayed. These are used to anchor upstanding wall 16 to foundations 20. The lower part of the rebars are preferably either ‘C’ or ‘L’ shaped, providing strength against the lateral forces caused by rising water levels outside barrier wall structure 14. Rebars are preferably set at pre-determined intervals along the line of wall structure 14 and emerge vertically from foundations 20 to a height just below the top of barrier wall 14. Rebars are advantageously configured in a staggered sequence along the length of wall 14, with each successive rebar emerging on either the front or back face of the wall. Construction panels are cut to pre-determined dimensions and lowered in position between the staggered rebars. A hydrostatic layer is preferably laid on the concrete beneath the panels to increase waterproofing, with a bitumen layer advantageously used in addition, where appropriate. Binding wire can be used to join the panel's wire mesh to the rebars, creating a rigid construction ready for the concrete spray (spraycrete) layer. Apertures or gaps are left in barrier 14 to allow removable waterproof panels or gates to be placed at access points, such as pedestrian gates and driveways. Once formed, wall 16 represents a strong, impermeable barrier preventing, or at least reducing the likelihood of, surface water reaching into protected zone 22.

In some preferred embodiments, drain system 32-34 includes one or more trenches of approximately 400 mm (width)×400 mm (depth) excavated around the property inside barrier wall 14, with 10 mm pea shingle backfill and a porous membrane lining and perforated land drainage pipes. Dimensions are typically determined on the basis of the site survey. Each trench can be excavated to a suitable depth and width and typically will surround property 12 but can in some cases only partially do so. A porous membrane is laid into the trench floor and sides to create a particle barrier while allowing the ingress of water into the trench. Perforated land drains are laid onto a bed of pea shingle at an inclination down to sump 30 and then backfilled to the top of the trench. One end of the pipes 32-34 enters sump 30 to allow waste water to be collected.

As ground water underneath property 12 rises, the membrane and shingle allows the water to enter the perforated drains and from there flow down the incline into sump 30. Surface water caused by heavy rainfall inside barrier 14 can also enter the land drains from the top of the trench, soaking through the shingle to be collected and carried to sump 30. The differential in pressure created by the water as it exits into sump 30 ensures, or at least increases the chance of, rapid draining of the trench.

In a standard installation subsurface barrier 20 can typically have a depth of around 1.5 meters, while drains 32-34 will be spaced around 1 meter from subsurface barrier 20 and be at a depth of around 1.5 meters also or a little higher, that is closer to the ground surface.

In addition to having drains adjacent to perimeter barrier 20, there can be provided drains within protected zone 22, for instance close to building 22, as depicted with drain 32 in FIG. 1. Drains 32, 34 are buried at a depth which is determined on the basis of the porosity of the soil and in some embodiments also on the expected amount of incoming water into protected zone 22 from historical records. The intention of drain system 32, 34 is to allow the removal of ground water from under the soil in protected zone 22, whether this is ground water emanating from outside the protected zone, ground water within the protected zone, rain water coming into the protected zone or a combination of these. Initial site surveys can determine on the basis of the expected water ingress into the protected zone and soil porosity not only the size of the drains and their ideal drain angle but also their position relative to perimeter wall 14 and depth to which they are buried. The aim is to ensure that the drains are able to remove sufficient volumes of water to maintain the water table below flooding levels, that is to no more than the level of the ground surface, or below ground surface, in order to prevent, or at least reduce the chance of, flooding in protected zone 22 and water ingress into building(s) 12. The provision of subsurface drains allow for a reduction in the level of water table 100. As illustrated in FIG. 1, drainage of ground water within protected zone 22 creates a curving water table between drain system 32, 34, sump 30 and buried barrier wall 20. It is the highest points of the water table which are relevant to the determination of the positioning of drains 32-34 and sump 30, as well as the depth of buried barrier wall 20, these highest points being dependent upon the ability of water to soak through the soil, that is the porosity of the soil, and the speed of drainage provided by drainage system 30-34. The curvature of the water table can be determined by determining the speed of flow of water through the soil, typically in liters per meter per second.

System 10, shown in FIG. 1, also includes a plurality of sensors 102, 104, 106 (shown in FIG. 8). First sensor 102 is located in sump 30 and is intended to determine whether the level of water in sump 30 has reached a threshold requiring pumping of water out of the sump, to outside protected zone 22. Second sensor 104 is located within protected zone 22 and in practice is positioned within a sump which in one embodiment is a buried tube having an open or water permeable lower end, for instance provided with a porous mesh across its lower end. The sump tube can have a depth of 2 meters. Located at the bottom of the sump tube is sensor probe 104 able to obtain a measure of the head or height of water within the tube and therefrom the state of impregnation of the ground. A third, optional, sensor 106 is disposed outside barrier wall 14, that is outside protected zone 22 and is arranged to detect the presence of ground water in order to give an early indication of possible flooding.

Further details of the sensors are given below and it is also to be understood that system 10 is not limited to the provision of three sensors. In some embodiments there can be fewer while in other embodiments there can be more. In addition, there can be provided a plurality of each sensor type, disposed in different locations within and/or outside protected zone 22. In its simplest form, system 10 can have no sensors 102-104, in which case there can be a continuously operable pump within sump 30, switchable only when there is no water in the sump. In other forms, there can be provided a water level sensor 102 in sump 30, in other more sophisticated systems both sump sensor 102 and ground sensor 104. Outlying sensor 106 can be provided in what could be described as a complete solution.

System 100 also includes a control unit 108, and can in practice be located within building 12 so that it can be operated by a user, for example an inhabitant of building 12 and so that system 100 can provide feedback and warnings to the user.

Control unit 108 is coupled to sensors 102, 104, and/or 106 and also to the pumping unit provided within sump 30. Control unit 108, in combination with the sensors 102, 104, and/or 106 and the pumping unit, is designed to optimize the control of water within protected zone 22 and specifically to reduce unnecessary pumping of water in order maximize efficiency of system 100, allowing natural water drainage when possible. Control unit 108 is also designed to warn users or inhabitants within protected zone 22, and optionally a remote management station, of the risk of flooding so that protective measures can be taken, such as closing gates and other openings in barrier wall 14.

FIGS. 2 to 7 show examples of elements of system 10.

FIG. 2 is a plan view showing a part of protected zone 22, surrounded by perimeter barrier 14 of the type disclosed in FIG. 1. As can be seen, perimeter barrier 14 has a shape and dimensions suitable for delimiting a desired perimeter zone around, in this example, building 12. There can be provided one or more access points 102 through barrier 14, for instance raisable or swingable panel gates. Building 12 includes, in this example, a utility or plant room 110 within which control unit 108 is located. Buried electrical duct 120 leads to sump 30 and in particular to the sensor located within the sump and to the draining pump. In some embodiments duct 120 has a diameter of 120 mm and is buried to a depth of around 500 mm.

Sub-surface channels 32, 34 are located adjacent perimeter barrier 14 and outside the perimeter of building 12, in practice being usefully located also for collecting rain water and other water landing onto the ground in protected zone 22. Channels 32, 34 are also positioned to collect sub-surface water from a rising water table or ground water coming from outside perimeter barrier 14, by virtue of being open at their upper sides.

FIG. 3 shows a cross-sectional view of an example of perimeter wall 14 suitable for the embodiment of FIG. 2 and other embodiments. The cross-section in FIG. 3 shows only a part of buried footing 20 of barrier wall 14. In FIG. 3, perimeter barrier 14 has a height of around 800 mm and includes buried ducts 122 for electrical wires to and from control unit 108, with optional electrical junction box 125 also being buried in wall 14.

On the outside of perimeter wall 14, that is outside protected zone 22, there is provided a small sump 130 at the foot of barrier wall 14 and having, in this example, a depth of around 250 mm. Disposed within sump 30 is water sensor 106. Sensor 106 includes wire 126 coupling the sensor to control unit 108. Sump 130 is typically protected from clogging, and preferably allows draining of water therein. In some embodiments there is a provision against the sump filling with debris. Sensor 106 is preferably of a type that triggers only once a threshold head of water has been reached, for example 200 mm. For example, hydrostatic sensors can be used.

FIG. 4 shows the arrangement of sensors and cabling for system 100 shown in FIGS. 1 and 2. FIG. 4 shows one embodiment and the number and positioning of the sensors can vary from one implementation to another.

In the example of FIG. 4, out-of-perimeter sensor 106 is arranged as per FIG. 3, sensor 104 is disposed within protected perimeter 22 and in this example adjacent perimeter wall 14, and third sensor 102 is disposed within sump 30. Ducting 120-124 connects sensors 102, 104 and 106 to control unit 108 located in utility or plant room 110 of building 108. Ducts 120-124 are preferably buried below ground surface.

Sensor 104 disposed within protected zone 22 is preferably located within a small sump, having a depth, for example, of around 250 mm but which could be up to 2000 mm deep or even deeper in dependence upon the nature of zone 22. Sensor 104 can sense the amount of ground water present within protected zone 22.

There can be provided other sensors similar to sensors 102, 104 and 106 shown in FIG. 4 and in particular a plurality of sensors 106 disposed outside perimeter wall 14 and/or a plurality of internal sensors 104 disposed in different locations within protected zone 22. Provision of a plurality of each of sensors 102, 104 and 106 can give a better indication of the existence and location of ground water either outside or inside protected zone 22.

FIG. 5 shows a plan view of corner 140 of perimeter barrier 14, as shown in FIGS. 2 and 4. As shown, electrical ducting 122 extends through the concrete structure of perimeter wall 14 to sensor 106. Electrical junction box 150, preferably buried within the structure of wall 14, can be provided for coupling electrical wires to and from sensor 106 and control unit 108.

Referring to FIG. 6, a first embodiment of sump 30 of system 10 is shown. Sump 30 can have a suitable cross-sectional shape, though typically is square, rectangular or circular. In the embodiments shown, sump 30 is circular cylindrical and has cylindrical upstanding wall 152, preferably made of concrete, to which is attached concrete base 154, which has a shape and size to conform with the outer perimeter of upstanding wall 152. The base and upstanding wall are preferably secured to one another in substantially liquid-tight manner, although in some embodiments can allow for water drainage there through, useful in cases where water is able to drain naturally from within protected zone 22, for instance as a result of dry ground conditions.

The top of sump 30 is covered by, in this example, concrete cover 156, although in other embodiments other materials can be used. In this example access 158 is a manhole. Access 158 can have brick walls, such that the entirety of sump 30 can be buried below the surface of ground 160, leaving access into the interior of sump 30 through manhole cover 162, typically made of metal.

In the example of FIG. 6, sump 30 is positioned adjacent upstanding wall 14. Disposed within sump 30 is pump unit 170 to which are connected lifting bale 172 and lifting chain 174, chain 174 extending towards manhole cover 162 and preferably being hooked nearby, so that pump unit 170 can be pulled up for maintenance or checking purposes. Pump unit 170 can have a single pump but preferably has a pair of pumps, which can be operated independently of one another or in unison.

Coupled to pump unit 170 is inlet tube 180 which has open upper end 182 disposed at about the same height as inlet pipe 180 into sump 130, the inlet pipe coupling to buried channels 32, 34. The height of pipe inlet 182 determines the maximum amount of water which can be stored within sump 30 without forcing evacuation of water from within sump 30. Inlet pipe 180 could have different heights, as desired.

Inlet pipe 180 acts as a safety element which ensures, or at least reduces the chance, that pump 170 will operate when sump 30 is filled with water, irrespective of what is detected by sensors 102, 104 and/or 106 of system 10. In other words, even if no further water is detected within protected zone 22, pump unit 170 will operate if water within sump 30 reaches above the height of upper end 182 of inlet pipe 80.

The outlet of pump unit 170 is coupled to outlet pipe 190, which in this example has closed upper end 192 which is secured to bracket 194, itself secured to concrete cover 156. In this example, outlet pipe 190 includes junction 200, to discharge pipe 202, which terminates at open end 204 beyond the perimeter of wall 14 and therefore outside the protected zone, in this example for discharge into drainage channel 210. Discharge pipe 202 is embedded within the structure of wall 14 and preferably fixed thereto in fluid tight manner such that there is no leakage through wall 14 at the location of pipe 202.

FIG. 7 shows a slightly modified version of sump 30 of system 10, compared to the embodiment shown in FIG. 6. In FIG. 7, the concrete structure of sump 30 is now shown. Inlet tube 184 from buried channels 32, 34 is disposed lower within sump 30 than the embodiment of FIG. 6 and pump inlet pipe 180 is closed and held by suitable guide support element 220.

The outlet pipe from pump unit 170 is blocked at its upper end 192, while junction 200 feeds pumped fluid into outlet pipe 204, which is coupled through flexible tubing 206 buried within ground 160 and exiting just at the top, exterior surface, of wall 14, thereby pumping water from sump 30 to the other side of barrier wall 14 and outside protected zone 22.

The specific design of sump 30 and the arrangement of pump unit 170 and inlet and outlet pipes can vary.

FIG. 8 shows the principal components of an example of control unit 108. Control unit 108 can include a variety of other components and elements for providing different functions, displays and warnings. Control unit 108 will typically include microprocessor 230, memory 232, input/output controller 234 and communications unit 235. Control unit 108 includes a series of inputs 236 for receiving signals from various sensors 102, 104 and 106, output 238 for controlling motor unit 170 and another input/output 240 for receiving user commands and for providing user data and warnings. The input/output can include a keypad, other control knobs and elements, a display and a visual or acoustic device.

Control unit 108 can be disposed within protected zone 22 and in the embodiments shown within building 12, but equally could be disposed at a remote monitoring station outside protected zone 22. It is envisaged that in most embodiments, control unit 108 will also include communications unit 235 for communicating information to and from central monitoring station 280, which can monitor operation of system 10 and the status of protected zone 22. Central monitoring station 280 can also communicate with a user, for instance over a standard telephone line or cellular telephone connection, and to a rapid response assistance service 280 when the risk of flooding within the protected zone exceeds a threshold risk.

The structure of system 10 can provide a complete multi-stage property level and area wide flood protection system.

Some preferred embodiments provide system 10 which is formed of five distinct elements working together to provide flood protection. The five elements include:

1) protective barrier wall 14 surrounding the property, designed to keep surface water away while allowing pedestrian and vehicle access through appropriate access ways;

2) A system of channels or drains 32, 34 within protected area 22 for collecting ground water as it rises from below property 12, feeding it into sump 30 of the pumping station. Drainage system 32, 34 can also absorb surface water from above caused by heavy rainfall;

3) sump 30 and pumping station 170 designed to remove the drained water to outside protected area 22. Pumping unit 170 preferably has dual pumps, which can be operated individually or together;

4) local control system 102-108 which includes one or more hydrostatic sensors, one or more rain gauges and a control module that monitors water levels and activates pump(s) 170; and

5) telemetry system 108 which monitors and manages water levels and pump station activity, sending alerts and alarms to designated recipients via SMS and email messages. The telemetry system can be incorporated into control unit 108 and include suitable transceiver unit 235 with input/output unit 234.

Control unit 108 can in some cases simply monitor water and warn the user of impending flooding, allowing the user to close barriers in wall 14 to close off zone 22. Control unit 108 makes use of sensors 102, 104 and 106 for this purpose. Pumping station 170 pumps water out of sump 30 when sensor 102 detects water above the predetermined threshold level and/or the water level reached the top of inlet pipe 180. In some embodiments, control unit 108 can make use of the signals from rain water sensor 104 to determine the rate of collection of water and to alter the rate of pumping of pump unit 170 to ensure, or at least increase the chances, that water is removed from protected zone 22 at a sufficient rate. Similarly, control unit 108 can allow rain water to drain naturally into the ground when sensor 104 does not sense water in the small sump in which it is located indicative of the ground being relatively dry and therefore able to absorb rainwater. Control unit 108 is also able to issue a warning when it is determined from the signals from the outside sensor or sensors 106 that flooding is occurring outside protected zone 22, that is outside barrier 14. The warning can be sent to the user and to remote monitoring station 280, such that the access points in wall 14 can be closed off In some embodiments, the access barriers can be automatically operated for instance by motors linked to control unit 108. As a result, system 100 provides comprehensive monitoring and management of protected zone and protection of zone 22.

Sump 30 and pumping station 170 includes three primary elements: input ports 184 into sump 30 from land drains 32-34, one or dual pumps 170 to evacuate the collected water and rising main pipe 190 to expel the collected water to outside barrier wall 14.

The size of sump 30, the capacity of pump 170 and the dimensions of rising main pipe 190 are determined for each individual zone 22 to be protected. In practice, a sump pit is excavated in a specified position inside barrier wall 14. In some embodiments this will be roughly 2 meters deep and 2.5 meters diameter. Sump 30 is lowered into position and anchored with poured concrete. Ports are bored into sump 30 for input 184 from the land drains which are secured in place with seals. A port for rising main 190 is also bored and pump(s) 170 and pipework 180/190 are fitted. The sump pit is then backfilled with shingle.

As the water level rises, sump sensor 102 activates the system and the pumps drain the water in sump 30 back to a pre-determined mean level, preferably outside barrier wall 14. This process repeats for as long as the water level rises above a set level.

Local control system 108 has three primary elements: hydrostatic sensor 102 placed at the bottom of sump 30, a series of remote sensors 104, 106 placed around protected area 22 (both inside and outside barrier wall 14) and digital control module 108 which is responsible for controlling pump(s) 170 fed by sensor inputs 236.

Hydrostatic sensor 102 is preferably fitted to the bottom of sump 30 and connected to control module 108. Sensor 102 is calibrated to read 0 bar with sump 30 empty. As the water level rises in sump 30, the increase in pressure is relayed to control module 108 which expresses the change in units (for instance millimeters) depth of water in sump 30. Once a set threshold is passed, module 108 initiates pumping station 170 which returns the water to the mean level. If the ingress of water is sufficiently rapid, a further threshold is crossed which activates both pumps simultaneously, increasing the water flow to the rising main. The threshold can be determined by the speed of replenishment of sump 30, the detected level of ground water by senor 104, the level of water outside protected zone 22 or combination of these. The control system 108, either internally or by external control from a user or remote management station 280 can also change the threshold level at which pumping commences to evacuate water from sump 30, which can also be useful when it is determined that there are high volumes of incoming water. For instance, control unit 108 and/or remote management station 280 could be designed to control pumping unit 170 to pump continuously when it is determined that a large volume of flood water is incoming The provision of dual pumps can also provide a backup pump facility in the event of failure of one of the two pumps.

Remote sensors 102 and 104, placed both inside and outside barrier wall 14, monitor water levels within and outside protected area 22. They are connected to control module 108, the latter being set to send alarms which in turn can alert designated recipients to close removable barriers in the wall, or perform other actions to protect the property. Specifically, system 10 is able to detect the onset of flooding, allowing users to take preventative measures before flooding actually occurs.

Rain gauge sensor 104 provides information on local precipitation and this data can be used with that from remote sensor 106, providing additional warning of impending flood conditions.

The preferred telemetry system includes the following elements: a communications module and transceiver 234, 235 housed in main control unit 108, a cellular telephone or satellite telephone communications facility for transmitting and receiving data, remote management station 250 (see FIG. 8) for monitoring and controlling system 10. Communications module 234-235 is connected to system processor 230 within main control unit 108. A mobile telephone sim card can be provided and configured to allow the exchange of data between designated recipients and also to dedicated remote management station 250.

As thresholds are exceeded and pumps 170 activated, data is fed to remote management station 250 which can be monitored and interacted with from internet enabled devices. Remote station 250 can configure local control system 108 to change the pumping parameters, for instance when it is detected that there is a high volume of water, as well as to send alerts to designated recipients. Furthermore, transceiver module 235 in control unit 108 can be configured to send alerts directly to designated persons, for example by a SMS alert.

System 10 disclosed herein can therefore provide:

a) barrier 14 built around property 12 or other area to be protected, which prevents, or at least reduces the likelihood and/or severity of, surface water entering protected area 22 while allowing access for pedestrians and vehicles;

b) drainage system 32-34 that removes ground water from below and surface water from above the property;

c) pumping system 170 that evacuates collected water to outside barrier 14;

d) local control system 108 that operates pumping station 30;

e) a telemetry system that allows remote management of the system and provides SMS and email alerts to designated recipients.

The asset can be a building but more typically is a zone which includes at least some ground surface. In one example, the zone can incorporate one of more buildings such as houses, gardens, driveways and so on. In another example, the zone can include a sports pitch, an industrial unit, hospital and so on, even a park area and pond.

The system and method provide a barrier wall, impervious to flood water, which can surround the asset. The system ensures, or at least increases the chance, that the asset can remain dry, not only from water ingress outside the asset and barrier wall but also, in the preferred embodiment, from water arriving into the asset such as rain water. The preferred embodiment acts to manage the water table within the asset (the area delimited by the barrier wall) such that the ground and buildings within the assets remain dry. In practice, this is achieved by managing the water table by the positioning of the drainage, sump(s) and pumping of water out of the asset. The water table in the asset can be different from that outside the asset, typically lower, ensuring that the asset remains dry.

The system and method do not require changes to the asset per se, such as structural changes to a building or the like. The structures within the asset can therefore be kept unchanged. Moreover, the system and method can maintain the asset in a virtually untouched condition, for instance a person's house and garden, with the barrier forming a perimeter wall, which can be finished in an aesthetically pleasing manner or otherwise in a manner consistent with the environment or form of the asset.

While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, that the invention is not limited thereto since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings. 

What is claimed is:
 1. A flood management system for protecting an asset from flood water comprising: (a) a perimeter barrier disposed alongside and around said asset, said perimeter barrier comprising: (i) an upstanding wall for blocking surface water ingress into said asset; and (ii) a subsurface barrier wall, said subsurface barrier wall separate from said asset; (b) a drainage system within said asset comprising a drainage unit disposed subsurface and adjacent said subsurface barrier wall; (c) a sump fluidically coupled to said drainage system for collecting water from said drainage system, said sump having a water level sensor configured to sense a water level in said sump; (d) a pumping unit connected to said sump; (e) a drainage conduit coupled to said pumping unit, said drainage conduit extending beyond said perimeter barrier; and (f) a trigger mechanism coupled to said water level sensor and said pumping unit, wherein said trigger mechanism is configured to activate said pumping unit when said water level in said sump exceeds a threshold level.
 2. The flood management system of claim 1, wherein said asset includes a building, wherein at least a part of said building is separate from said perimeter barrier.
 3. The flood management system of claim 1, wherein said asset includes an exposed ground surface.
 4. The flood management system of claim 1, wherein at least a part of said perimeter barrier has a height not exceeding 1.5 meters.
 5. The flood management system of claim 1, wherein said drainage unit is separate from said subsurface barrier wall.
 6. The flood management system of claim 5, where said drainage unit is about one meter from said subsurface barrier wall.
 7. The flood management system of claim 1, wherein said drainage unit is disposed at a depth substantially the same as the depth of said subsurface barrier wall.
 8. The flood management system of claim 1, wherein said drainage unit is connected to said sump at a depth lower than said threshold level.
 9. The flood management system of claim 1, wherein said threshold level is an acceptable water table level in a protected zone.
 10. The flood management system of claim 1, wherein said pumping unit comprises a pump, wherein said pump is activated when water flow is determined to exceed a threshold rate.
 11. The flood management system of claim 1, including a sensor configured to measure ground water inside said asset.
 12. The flood management system of claim 1, including a sensor configured to measure surface water outside said asset.
 13. The flood management system of claim 1 claim further comprising: (g) a control unit connected to a sensor and said trigger mechanism; wherein said said control unit includes: (i) a telemetry unit to monitor and manage water levels and pump unit activity; and (ii) a communications unit to send flood related alerts to a remote management station.
 14. A method of protecting an asset from flood water said method comprising: (a) forming a barrier alongside and around said asset, wherein said barrier comprises: (i) an upstanding wall for blocking surface water ingress into a protected zone; and (ii) a subsurface barrier wall, wherein said subsurface barrier wall is distinct from said asset; (b) forming a drainage system within said asset, said drainage system including a drainage unit disposed subsurface and adjacent to said subsurface barrier wall; (c) providing a sump subsurface in said protected zone, fluidically coupled to said drainage system for collecting water from said drainage system, wherein said sump has a water level sensor configured to sense water level in said sump and a pumping unit is connected to said sump; (d) providing a drainage conduit coupled to said pumping unit, wherein said drainage conduit extends beyond said barrier; (e) providing a trigger mechanism coupled to said water level sensor and said pumping unit, wherein said trigger mechanism is configured to activate said pumping unit when said water level in the sump exceeds a threshold level.
 15. The method of claim 14, wherein said asset includes a building and wherein said perimeter barrier is at least partially spaced from said building.
 16. The method of claim 14, wherein said asset includes an exposed ground surface.
 17. The method of claim 14, further comprising: (f) determining a soil porosity where said barrier is to be formed ;and (g) determining the depth of said subsurface barrier wall based at least part on the basis of said soil porosity.
 18. The method of claim 17, wherein said subsurface barrier wall has a greater depth in more porous soil and a lesser depth in less porous soil.
 19. The method of claim 18, further comprising: (h) spacing said drainage unit from said barrier on the basis of determined soil porosity.
 20. The method of claim 19, further comprising: (i) determining a depth to place said drainage unit on the basis of determined soil porosity.
 21. The method of claim 14 further comprising: (f) disposing in said asset a first sensor configured to measure surface or ground water within said asset; and (g) disposing outside said asset a second sensor configured to measure surface or ground water outside said asset.
 22. The method of claim 14 further comprising: (f) providing a control unit coupled to said sensor, wherein said control unit (i) is connected to said trigger mechanism (ii) includes a telemetry unit to monitor and manage water levels and pump unit activity; and (iii) includes a communications unit configured to send flood related alerts to a remote management station. 